import java.util.Arrays;
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: dell
 * Date: 2023-12-03
 * Time: 17:15
 */
public class test4 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            String str=in.nextLine();
            int sou=(int)('z'-'A')+1;
            int[] arr=new int[sou];
            for(int i=0;i<str.length();i++){
                char ch=str.charAt(i);
                int b=(int)(ch-'A');
                arr[b]++;
            }
            for(int j=0;j<sou;j++){
                if(arr[j]!=0){
                    System.out.print((char)(j+65));
                    //System.out.println(Arrays.toString(arr));
                }
            }

        }
    }
    public static void main1(String[] args) {
        String s=", , , ,        a, eaefa";
//        String[] array=s.split(" ");
//        boolean b =s.isEmpty();
//        System.out.println(b);
//        int a=array.length;
//        System.out.println(a);
        boolean b=s.isEmpty();
        if (s.equals(" "));
        String str=s.toLowerCase();
        char[] arr=s.toCharArray();
        System.out.print((char)(97));

    }
}